Image pickup apparatus for generating wide dynamic range synthesized image

ABSTRACT

An image pickup apparatus having function for synthesizing image signals corresponding to a plurality of frames of different exposure amounts to generate wide dynamic range, synthesized image is provided with: at least two control means among a taking control means based on a normal taking mode, a taking control means based on a forced wide dynamic range taking mode, and a taking control means based on an automatic wide dynamic range taking mode for selectively generating wide dynamic range, synthesized image automatically on the basis of object information or information set for the image taking; and means for selectively setting one image taking mode out of the taking modes respectively corresponding to the two control means. It is thereby possible to take image by selecting one image taking mode from at least two taking modes among the normal taking mode, the forced wide dynamic range taking mode, and the automatic wide dynamic range taking mode.

RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.09/395,935 filed on Sep. 14, 1999, which is incorporated by reference inits entirety. Priority under 35 U.S.C. 120 is hereby claimed for benefitof the filing date of U.S. patent application Ser. No. 09/395,935.

BACKGROUND OF THE INVENTION

The present invention relates to image pickup apparatus having afunction for obtaining a wide dynamic range, synthesized image bysynthesizing image signals corresponding to a plurality of frames ofdifferent exposure amounts outputted from an image pickup device.

Solid-state image pickup devices such as CCD image pickup device aregenerally used in image pickup apparatus as TV camera, video camera,digital camera, etc. There is a problem however that the dynamic rangeof a solid-state image pickup device is much narrower than that of asilver halide photographic film.

To eliminate this problem, there have been proposed techniques in whichimage signals corresponding to two frames taken at different exposureamounts are read out from a single image pickup device and aresynthesized to obtain an image having increased dynamic range. Forexample, an image pickup apparatus having the following construction isdisclosed in Japanese Patent Publication No. 2522015.

In particular, a disclosure has been made with respect to an imagepickup apparatus including: image pickup means for converting objectimage into electrical signals; image pickup control means forselectively executing a first mode or second mode, said first mode forsuccessively outputting images of different exposure amounts in cyclesby cyclically changing charge accumulation time at the image pickupmeans, image portions at suitable level being synthesized to form asynthesized frame of said predetermined cycle by respectively comparingsignal level of each portion of a plurality of frames of differentexposure amounts outputted from said image pickup means with apredetermined reference value, said second mode for providing output byusing a constant charge accumulation time at said image pickup means;and switch control means for switching the image pickup control means tothe first mode when an occurrence of object having a large luminancedifference within a frame is detected in said second mode by comparingsignals obtained from said image pickup means in said second mode with apredetermined level. This image pickup apparatus, when in the firstmode, is capable of obtaining an image of which all the portions of aframe are at suitable signal level. Even when object having a largeluminance difference exists within a frame as in a backlightedcondition, lack of detail at high level portion thereof for example doesnot occur within the frame and it is in effect possible to provide awider dynamic range. Further, without an operator's decision on theconditions of object, etc., it is automatically switched to the firstmode by the switch control means when object having a large luminancedifference exists within a frame in the second mode, making it possibleto automatically correct a backlighted condition, etc.

In the above described image pickup apparatus as disclosed in JapanesePatent Publication No. 2522015, however, switching to the first mode forgenerating wide dynamic range, synthesized image is automatically madewhen an existence of object having a large luminance difference isdetected within a frame which is obtained in the second mode. Noconsideration has been made therein about a normal image taking modewhere the generation of wide dynamic range, synthesized image isautomatically prohibited or about a mode for forcing the generation ofwide dynamic range, synthesized image. This results in a problem of areduced operability. Further, there is another problem in the imagepickup apparatus as disclosed in the abovementioned publication that,since means for displaying ON/OFF status of the generation processing ofwide dynamic range, synthesized image are not provided, it is difficultto identify the switched state of ON/OFF of synthesized image.

SUMMARY OF THE INVENTION

It is a main object of the present invention to provide an image pickupapparatus in which image can be taken by selecting a mode from at leasttwo modes among a normal taking mode, a forced wide dynamic range takingmode, and an automatic wide dynamic range taking mode.

In a first aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: at least two control means among anormal taking control means based on a normal taking mode for generatingimage pickup signals corresponding to one frame from the image pickupmeans, a forced wide dynamic range taking control means based on aforced wide dynamic range taking mode for forcing a generation of widedynamic range, synthesized image, and an automatic wide dynamic rangetaking control means based on an automatic wide dynamic range takingmode for selectively generating wide dynamic range, synthesized imageautomatically on the basis of object information or information set forthe image taking; and means for selectively setting one image takingmode out of the taking modes respectively corresponding to these controlmeans.

By such construction, operability can be improved such that it ispossible with a single image pickup apparatus to take image by selectingone taking mode from at least two modes among the normal taking mode,the forced wide dynamic range taking mode, and the automatic widedynamic range taking mode. The above main object is therebyaccomplished.

It is another object of the invention to provide an image pickupapparatus in which discrimination can be made as to whether or not it issuitable for the generation of synthesized image to take image on thebasis of information based on previously taken image data, informationobtained before the taking of image, or information set on the imagepickup apparatus.

In a second aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes means for displaying as a suitabilitydetermining information of the synthesized image generating process atleast one information out of information based on previously taken imagedata, information obtained before the taking of image, and informationset on the image pickup apparatus before the taking of image that isrequired in determining whether a suitable wide dynamic range,synthesized image can be obtained or not.

By thus displaying the suitability determining information, it ispossible, in the case of manually setting the generation processing ofsynthesized image, to make discrimination as to whether or not apreviously taken image data is an image data suitable for the generationof synthesized image by the displaying of information based on thepreviously taken image data; it is also possible by the displaying of aninformation obtained before the taking of image or information setbefore the taking of image to determine whether the generation ofsynthesized image based on such information is suitable or not. Further,in the case where the generation processing of synthesized image isautomatically performed on the basis of the above described information,it is possible to confirm the information according to which thegeneration of synthesized image is made unsuitable. The above object isthereby accomplished.

It is still another object of the invention to provide an image pickupapparatus in which suitability for the generation processing ofsynthesized image can be quite readily confirmed.

In a third aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: means for determining the suitabilityto the generation processing of synthesized image of at least oneinformation out of information based on previously taken image data,information obtained before the taking of image, and information set onthe image pickup apparatus before the taking of image that is requiredin determining whether a wide dynamic range, synthesized image can besuitably generated or not; and display means for displaying the resultof determination at the determination means.

By thus providing the means for displaying a determination result as towhether it is suitable for synthesized image generation processing ornot, the suitability for the synthesized image generation processing canbe quite readily confirmed. The above object is thereby accomplished.

It is yet another object of the invention to provide an image pickupapparatus in which the cause for unsuitableness of synthesized image canbe confirmed so that the image taking conditions be changed to achievesuitable conditions.

In a fourth aspect of the invention, the display means of the imagepickup apparatus according to the third aspect displays informationdetermined as unsuitable as N.G. information when it is determined asunsuitable by the determination means.

Since information becoming unsuitable is thus displayed as N.G.information, the cause of unsuitableness can be confirmed and it isthereby possible to achieve suitable conditions by changing the imagetaking conditions. The above object is thereby accomplished.

It is a further object of the invention to provide an image pickupapparatus in which it is possible to confirm the level of change in theimage taking conditions for achieving suitableness.

In a fifth aspect of the invention, the display means of the imagepickup apparatus according to the third or fourth aspect displays theresult of determination at the determination means as a numericalparameter of information and at the same time displays a suitable rangefor synthesizing process of the information numeric parameter.

By thus displaying a suitable range of synthesizing process togetherwith a numeric parameter of information, it is possible to confirm thelevel of change in the image taking conditions for achievingsuitableness. The above object is thereby accomplished.

It is a further object of the invention to provide an image pickupapparatus capable of preventing an unsuitable taking of image resultingin a degraded picture quality, etc., from being executed.

In a sixth aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: at least two control means among anormal taking control means based on a normal taking mode for generatingimage pickup signals corresponding to one frame from the image pickupmeans, a forced wide dynamic range taking control means based on aforced wide dynamic range taking mode for forcing a generation of widedynamic range, synthesized image, and an automatic wide dynamic rangetaking control means based on an automatic wide dynamic range takingmode for selectively generating wide dynamic range, synthesized imageautomatically on the basis of object information or information set forthe image taking; means for selectively setting one image taking modeout of the taking modes respectively corresponding to these controlmeans; a suitability determination means for determining whether or notinformation obtained as the conditions of generation processing for thegeneration of wide dynamic range, synthesized image is the informationsuitable for the generation processing of wide dynamic range,synthesized image; and display means for displaying “inconsistency” whenthe taking mode set at the mode setting means and the result ofdetermination made at the suitability determination means are notsuitable to each other.

By thus displaying “inconsistency” when the set taking mode and theresult of determination at the suitability determination means are notsuitable to each other, it is possible to prevent an unsuitable takingof image resulting in a degraded picture quality, etc., from beingexecuted. The above object is thereby accomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which the difference in exposure conditions of aplurality of images to be taken and the dynamic range if they arecombined into a synthesized image can be recognized.

In a seventh aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes means for displaying an exposureamount ratio of the image signals corresponding to a plurality of framesof different exposure amounts.

By thus displaying an exposure amount ratio of the image signalscorresponding to a plurality of frames of different exposure amounts, itis possible to recognize the difference in exposure conditions of theplurality of images to be taken and the dynamic range if they arecombined into a synthesized image. The above object is therebyaccomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which confirmation can be made as to an occurrenceof correction of exposure amount ratio and at the same time shift in theexposure amount ratio and the dynamic range based on the correctedexposure amount ratio can be confirmed.

In an eighth aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: means for correcting exposure amountof the image signals corresponding to a plurality of frames of differentexposure amounts; and display means for displaying operation status ofthe means for correcting exposure amount.

By thus providing the means for displaying operation status of thecorrection means of exposure amount ratio, confirmation can be made asto an occurrence of correction of exposure amount ratio. And at the sametime, by displaying the exposure amount ratio before and after thecorrection, it is possible to confirm shift in the exposure amountratio, the dynamic range based on the corrected exposure amount ratio,etc. The above object is thereby accomplished.

It is a further object of the invention to provide an image pickupapparatus in which confirmation can be made as to an occurrence ofcorrection of motion and a resulting degradation in image quality can beeasily noticed.

In a ninth aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: means for detecting motion of anobject image; means for correcting amount of motion when the motionamount detected at the motion detection means is within an allowablerange for correction; and display means for displaying operation statusof the motion amount correction means.

By thus providing the means for displaying operation status of themotion correction means, an occurrence of correction of motion can beconfirmed. Further, since the fact of the occurrence of motion can beseen from the displaying of “Motion Correction”, the resultingdegradation in image quality can be easily noticed. The above object isthereby accomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which confirmation can be readily made whether asynthesizing process will be actually performed or whether it has beenperformed.

In a tenth aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: at least two control means among anormal taking control means based on a normal taking mode for generatingimage pickup signals corresponding to one frame from the image pickupmeans, a forced wide dynamic range taking control means based on aforced wide dynamic range taking mode for forcing a generation of widedynamic range, synthesized image, and an automatic wide dynamic rangetaking control means based on an automatic wide dynamic range takingmode for selectively generating wide dynamic range, synthesized imageautomatically on the basis of object information or information set forthe image taking; means for selectively setting one image taking modeout of the taking modes respectively corresponding to these controlmeans; and display means for displaying ON/OFF status of the generationprocessing of wide dynamic range, synthesized image on the basis of thetaking mode set at the mode setting means.

By thus providing the display means for displaying ON/OFF status of thegeneration processing of wide dynamic range, synthesized image, it ispossible to readily confirm whether a synthesizing process will beactually performed or whether it has been actually performed. The aboveobject is thereby accomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which it is possible to confirm an actualsynthesized image.

In an eleventh aspect of the invention, there is provided an imagepickup apparatus including: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes display means for displayingsynthesized image outputted from the means for generating wide dynamicrange, synthesized image.

By thus displaying wide dynamic range, synthesized image, it is possibleto confirm an actual synthesized image. The above object is therebyaccomplished.

It is a further object of the invention to provide an image pickupapparatus capable of taking image with improving image quality.

In a twelfth aspect of the invention, there is provided an image pickupapparatus including: image pickup means capable of taking images of thesame object at a plurality of different exposure amounts to generateimage signals corresponding to a plurality of frames of differentexposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: at least two control means among anormal taking control means based on a normal taking mode for generatingimage pickup signals corresponding to one frame from the image pickupmeans, a forced wide dynamic range taking control means based on aforced wide dynamic range taking mode for forcing a generation-of widedynamic range, synthesized image, and an automatic wide dynamic rangetaking control means based on an automatic wide dynamic range takingmode for selectively generating wide dynamic range, synthesized imageautomatically on the basis of object information or information set forthe image taking; means for selectively setting one image taking modeout of the taking modes respectively corresponding to these controlmeans; a suitability determination means for determining whetherinformation obtained as the conditions of generation processing for thegenerating wide dynamic range, synthesized image is the informationsuitable for the generation processing of wide dynamic range,synthesized image; and means for directing a change in the setting ofparameter of the information or in the setting of taking mode ordirecting a retake when the taking mode set at the mode setting meansand the result of determination made at the suitability determinationmeans are not suitable to each other.

When the taking mode and the content of information parameter areunsuitable to each other, if before the taking of image, the means fordirecting a change in the setting of taking mode or informationparameter is provided so that image can be taken with improving imagequality. Further, if after the taking of image, since a retake isdirected, it is similarly possible to take image with improving imagequality. The above object is thereby accomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which dynamic range and/or suitable exposure amountcan be recognized by numeric values.

In a thirteenth aspect of the invention, there is provided an imagepickup apparatus including: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes means for displaying brightnessinformation of a desired portion of object together with an image of theobject.

By thus providing the means for displaying brightness information of adesired portion of object together with an object image, the displayingof luminance of the darkest portion and the brightest portion of theobject for example makes it possible to recognize dynamic range and/orsuitable exposure amount by numeric values. The above object is therebyaccomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which dynamic range of synthesized image can be setat will by a visual method.

In a fourteenth aspect of the invention, there is provided an imagepickup apparatus including: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: means for designating a plurality ofdesired regions of a displayed image; means for obtaining luminanceinformation of the regions designated by the designating means; andmeans for adjusting exposure amounts of the plurality of images suchthat suitable luminance levels are achieved of the respectively obtainedluminance information at the time of generating a wide dynamic range,synthesized image.

Since exposure amounts of the plurality of images are thus adjusted sothat luminance information of the designated, desired regions is ofsuitable luminance levels at the time of generating wide dynamic range,synthesized image, it becomes possible to set wide dynamic range of thesynthesized image at will by a visual method. The above object isthereby accomplished.

It is a further object of the present invention to provide an imagepickup apparatus in which object regions wished to be included in thewide dynamic range of synthesized image can be readily designated.

In a fifteenth aspect of the invention, the means for designating aplurality of desired regions of image of the image pickup apparatusaccording to the fourteenth aspect includes means for marking by settingand locking a previously set, framed narrow region on a target object inthe image.

By constructing the designation means in this manner, the object regionswished to be included within the dynamic range of synthesized image canbe readily designated. The above object is thereby accomplished.

It is a further object of the invention to provide an image pickupapparatus in which dynamic range of synthesized image can be set at willby a visual method.

In a sixteenth aspect of the invention, there is provided an imagepickup apparatus including: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means. It further includes: display means for respectivelydisplaying a plurality of images of different exposure amounts; andmeans for setting the exposure amounts of the images displayed by thedisplay means to desired exposure amounts, the dynamic range ofsynthesized image being set on the basis of the exposure amountsrespectively set for the plurality of images.

Since the exposure amounts of the plurality of displayed images are thusset to desired exposure amounts and the dynamic range of synthesizedimage is set on the basis of the set exposure amounts, it becomespossible to set the dynamic range of synthesized image at will by avisual method. The above object is thereby accomplished.

It is a further object of the invention to provide AE apparatus of imagepickup apparatus in which time-lag in shutter and dissipation power canbe reduced.

In a seventeenth aspect of the invention, there is provided an AE devicein image pickup apparatus including: means for controlling exposureamount to an image pickup device; control means for setting a pluralityof different exposure amounts to the means for controlling exposureamount; means for acquiring a plurality of output information based onthe plurality of exposure amounts set from the image pickup device;means for generating synthesized output information of wide dynamicrange by synthesizing the plurality of acquired output information; andmeans for deciding exposure amounts from the synthesized outputinformation.

By such configuration of AE device, suitable values of exposure can bedecided in a short time period on the basis of the plurality of outputinformation of different exposure amounts and it is possible to solvethe problem of time-lag in shutter and/or dissipation power. The aboveobject is thereby accomplished.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram showing an overall, electrical construction ofa digital camera, being an embodiment of image pickup apparatusaccording to the present invention.

FIG. 2 shows an external construction of the embodiment shown in FIG. 1.

FIG. 3 is a block diagram showing an example of construction of thecamera signal processing circuit in the embodiment shown in FIG. 1.

FIG. 4 is a block diagram showing another example of construction of thecamera signal processing circuit.

FIGS. 5A and 5B show a manner of displaying at LCD display section whensetting the respective taking modes.

FIGS. 6A to 6C show an example of construction of switch for settingimage taking mode.

FIG. 7 shows a manner of displaying the suitability determininginformation obtained in connection with a wide dynamic range imagetaking.

FIGS. 8A and 8B show a manner of displaying the determination resultsfor respective information parameters to be used as the conditions forwide dynamic range image taking and the result of determination as towhether the wide dynamic range image taking is suitable as a whole.

FIG. 9 shows a manner of displaying information on motion of the object.

FIGS. 10A and 10B show displaying manner at the time of an inconsistencybetween the result of determination of wide dynamic range suitabilityand the set image taking mode.

FIGS. 11A and 11B show a manner of displaying exposure amount ratio ofthe two frames to be synthesized and dynamic range of the synthesizedimage.

FIGS. 12A and 12B show a manner of displaying correction of exposureamount ratio.

FIGS. 13A and 13B show a manner of displaying correction of motion.

FIG. 14 explains the stages at which ON/OFF status of the generationprocessing of wide dynamic range, synthesized image is displayed.

FIGS. 15A and 15B show a manner of displaying ON/OFF of wide dynamicrange synthesizing process.

FIG. 16 shows a manner of displaying a list of taking modes with respectto all of the previously recorded images.

FIG. 17 shows a manner of displaying the image taking information forthe generation of wide dynamic range, synthesized image as superimposedon the wide dynamic range, synthesized image.

FIGS. 18A and 18B show a manner of displaying by switching between annormally taken image and a wide dynamic range, synthesized image.

FIG. 19 shows a manner of concurrently displaying a normally taken imageand a wide dynamic range, synthesized image.

FIGS. 20A and 20B show a manner of displaying by switching between ashort-time exposure image and a long-time exposure image before theirwide dynamic range synthesizing process.

FIG. 21A and FIG. 21B show a manner of displaying when changing thesetting of information parameters or retaking image.

FIGS. 22A to 22C show a manner of displaying brightness information of adesired portion of the object.

FIGS. 23A and 23B show a manner of designating portions of the object soas to set a dynamic range by using a visual method.

FIGS. 24A and 24B show a manner of displaying a short-time exposureimage and a long-time exposure image so as to set a dynamic range ofsynthesized image on the basis of exposure amount ratio of the twoimages.

FIG. 25 is a block diagram showing an embodiment of AE apparatus fordetermining a suitable value of exposure on the basis of a plurality ofoutput information of different exposure amounts.

FIG. 26 is a timing chart for explaining an operation of AE apparatusshown in FIG. 25.

FIGS. 27A and 27B show a manner of synthesizing process of two images ofdifferent exposure amounts in order to obtain a suitable value ofexposure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some embodiments of the present invention will now be described. First,a description will be given below by way of a block diagram shown inFIG. 1 with respect to an overall, electrical construction of a digitalcamera which is a first embodiment of the image pickup apparatusaccording to the invention. Referring to FIG. 1, denoted by numeral 1 isa single-plate color CCD image pickup device for photoelectricallyconverting an optical signal into an electrical signal. It includes anelectronic shutter function. An object light is inputted to CCD imagepickup device 1 through a lens 2 and a stop/shutter mechanism 3. Anoutput of CCD image pickup device 1 is amplified at an amplifier 4 afterremoved of noise for example at a correlation double sampling circuit.An analog-to-digital converter 5 converts the output of the amplifier 4outputted as analog data into digital data. A camera signal processingcircuit 6 processes signals-from CCD image pickup device 1 as an imagedata. Those denoted by numeral 7 include an AF detection circuit forextracting AF (autofocus) information to control focus, an AE detectioncircuit for extracting AE (auto exposure) information to controlexposure, and an AWB detection circuit for extracting AWB (auto whitebalance) information to set white balance, by using such as the imagepickup signals from the CCD image pickup device 1 before the main takingof image. Output signals from the AF, AE, AWB detection circuit 7provide through CPU 8 AF information to lens 2, AE information tostop/shutter mechanism 3, and AWB information to the camera signalprocessing circuit 6.

Numeral 9 denotes a compression circuit (JPEG) for compressing datavolume. The image data compressed at the compression circuit 9 isrecorded at memory card 15 through memory card I/F 14. Memory controller10 and DRAM 11 are used as working memory when performing colorprocessing of image data, etc. A display circuit 12 and LCD display unit13 are used for example to confirm the image taking conditions byreading out and displaying data recorded at the memory card 15. Denotedby numeral 16 is a personal computer I/F for transmitting data recordedon the memory card 15 to a personal computer 17. It should be notedthat, in FIG. 1, numeral 18 denotes a timing generator which generatestiming pulse for driving the CCD image pickup device 1. It drives theCCD image pickup device 1 in accordance with control of CPU 8. A strobemechanism 19 is controlled through CPU 8 by AE information which is tobe obtained before the main taking of image. It effects control as towhether strobe should be emitted or not and controls the quantity oflight of the strobe emission. Numeral 20 denotes input keys of CPUthrough which one is able to effect setting of various types of imagetaking modes and image taking conditions, driving of various switches,etc.

An external construction of the digital camera according to the presentembodiment will now be described by way of an outside drawing as viewedfrom the photographer's side as shown in FIG. 2. In this embodiment, theapparatus body is constituted by two exterior members, a front cover 21and a rear cover 22. A taking lens 23 on a front surface and a turn typestrobe 24 on an upper surface are respectively provided on the frontcover 21. The strobe 24 in FIG. 2 is shown in its unused state. Further,a power switch button 25 for turning ON/OFF a power supply of theapparatus is provided on the upper surface of the front cover 21. Upondepression of the power switch button 25, an internally located powerswitch is operated and, corresponding to this, CPU 8 controls ON/OFF ofthe power supply.

Provided on the circumference of the power switch button 25 is aring-like R/P changeover switch button 26 which is turned to beoperated. The R/P changeover switch button 26 is to switch betweenrecording and playback. By turning it about the power switch button 25to operate an internally located R/P switch, switching ofrecording/playback modes is controlled. Further, a release button 27 isprovided toward the right end on the upper surface of the front cover21. By pressing down the release button 27 at the time of recording, arelease switch at the inside is turned ON so that object image isrecorded to the memory card 15. A zoom knob 28 is provided on thecircumference of the release button 27, the zoom knob 28 being soconstructed as to turn about the release button 27. When the zoom knob28 is turned clockwise or counterclockwise, a zoom focus mechanism atthe inside of the taking lens 23 is controlled in linkage with a zoomswitch in accordance with previously set directions so that image to betaken is enlarged/reduced.

An ocular section 29 of the optical finder for confirming image to betaken is disposed at an upper left end portion of the rear cover 22.Four mode setting buttons 30 are disposed side by side along an uppersurface slope of the rear cover 22 toward the right of the finder ocularsection 29. The mode setting buttons 30 are used in setting image takingmode, ON/OFF of strobe, forced emission, compression factor or shutterspeed at the time of recording, etc., and are respectively provided withinternally located, corresponding mode switches. An image LCD displaysection (color liquid crystal display section) 31 is disposed on theback of the rear cover below the finder ocular section 29. A recordedobject image or the like is displayed on the image LCD display section31 and it is used to confirm previously taken images, etc. Further,ON/OFF of displaying is possible on the image LCD display section 31 ofsuch non-image, incidental information at the time of image recording asimage taking modes, various image taking conditions, and in additionrecording date and time, frame number, etc. Four menu setting buttons 32are arranged in a vertical direction on the right side of the image LCDdisplay section 31, these buttons from the top to the bottom being a“menu” button, “+” button, “−” button, and “OK” button. It should benoted that the above described power switch button 25, R/P changeoverswitch button 26, release button 27, mode setting buttons 30, menusetting buttons 32, etc., correspond to the input keys 20 as shown inFIG. 1.

Referring to FIG. 2, a right side portion of the digital cameraaccording to this embodiment constitutes a holding part 33 correspondingto the so-called grip, for holding it by the right hand when takingimage. A lid 34 for memory card is disposed at a corner on thephotographer's side of the holding part 33 and a lid 35 for battery isdisposed adjacent to the memory card lid 34. Further, an LCD 36 fordisplaying various information is disposed in the vicinity of therelease button 27 on the upper surface of the front cover 21.

Recording operation of the image pickup apparatus having the abovedescribed construction will now be described. First, the power switchbutton 25 is pressed down to introduce power and recording mode is setby the R/P changeover switch button 26. An image taking mode is then setby the mode setting buttons 30. In the present embodiment, those whichcan be selected and set by the input keys 20, i.e., mode setting buttons30 as image taking mode are: a normal image taking mode for obtainingimage pickup signals corresponding to one frame by one taking of imagebased on normal AE information; an automatic wide dynamic range imagetaking mode for automatically performing ON/OFF control of wide dinamicrange (hereinafter referred to as: SL (Super Latitude)) image taking forobtaining SL synthesized image on the basis of image informationcorresponding to previously taken two frames, various informationobtained before the taking of image, information set on the camerabefore the taking of image, etc., in which image signals correspondingto two frames of different exposure amounts are generated andsynthesized by taking image of the same object twice at differentexposure amounts; and a forced SL image taking mode for forcing theabove described SL image taking. Based on the inputting and setting ofsuch modes, an image taking mode is switched to another by CPU 8.

If the apparatus is set to the normal taking mode where SL image takingis not to be performed, image pickup signals obtained by one taking ofimage on the basis of a normal AE information are converted into digitalsignal at the analog-to-digital converter 5, subjected to apredetermined signal processing at the camera signal processing circuit6, and then compressed at the compression circuit 9 to be recorded tothe memory card 15.

When the apparatus is set to the automatic SL taking mode, on the otherhand, if ON/OFF of the generation processing of SL synthesized image isto be automatically performed on the basis of information, such asmotion of the object, obtained from previously taken image signalscorresponding to two frames of different exposure amounts, thegeneration processing of automatic SL synthesized image is performed byusing a camera signal processing circuit constructed as shown in FIG. 3.

Included in FIG. 3 are: 6-1, SE memory for storing short-time exposureimage data; 6-2, LE memory for storing long-time exposure image data;6-3, a multiplier for multiplying a short-time exposure image data readout from the SE memory 6-1 by an exposure amount ratio A(=LE/SE) of theshort-time exposure image and long-time exposure image; 6-4, asynthesizing circuit for forming by means of synthesis a wide dynamicrange, synthesized image from the short-time exposure image data afterthe multiplication and the long-time exposure image data read out fromthe LE memory 6-2; 6-5, a compression circuit for compressing the SLsynthesized image obtained at the synthesizing circuit 6-4; 6-6, asignal processing circuit for subjecting the long-time exposure imagedata read out from the LE memory 6-2 to such processing as γ-correctionand edge enhancement; and 6-7, a selector for providing an output byswitching based on control signal from CPU 8 between the SL synthesizedimage from the synthesizing circuit 6-4 and the long-time exposure imagedata having been subjected to signal processing at the signal processingcircuit 6-6. Further, denoted by numeral 8A is a motion detectingsection provided internally of CPU 8, for detecting motion in the objectbased on the short-time exposure image data and long-time exposure imagedata read out from the SE memory 6-1 and LE memory 6-2. Switching of theselector 6-7 is controlled on the basis of the output of the motiondetecting section 8A.

A description will now be given with respect to an operation of thusconstructed camera signal processing circuit 6. First, a short-timeexposure image data and a long-time exposure image data of thesame-object taken at CCD image pickup device 1 are temporarily stored toSE memory 6-1 and LE memory 6-2. The image data are then transmitted toCPU 8 from the two memories 6-1, 6-2 to detect motion of the object atthe motion detecting section 8A on the basis of the two image data ofdifferent exposure amounts. When no motion is detected at the motiondetecting section 8A, a wide dynamic range, synthesized imagesynthesized at the synthesizing circuit 6-4 on the basis of the imagedata read out from the two memories 6-1, 6-2 and compressed at thecompression circuit 6-5 is outputted through the selector 6-7 which iscontrolled by CPU 8. On the other hand, if a motion is detected, theoutput of synthesized image is turned OFF and the long-time exposureimage data read out from the LE memory 6-2 and subjected to signalprocessing at the signal processing circuit 6-6 is outputted through theselector 6-7. A motion is thus detected on the basis of previously takenimage data so that it is possible to prevent a failed, synthesized imagefrom being outputted when the object has been moved at the time oftaking two images at different exposure amounts.

Further, if ON/OFF of the generation processing of SL synthesized imageis to be automatically switched by detecting a motion of the object onthe basis of information obtained before the taking of image, such as AFsignal from an external AF-circuit by providing the external AF circuit,the generation processing of automatic SL synthesized image is performedby using a camera signal processing circuit constructed as shown in FIG.4.

In this case, as shown in FIG. 4, only the frame memory 6-1 for storingshort-time exposure image data is included as frame memory in the camerasignal processing circuit 6′. The short-time exposure image data istaken into SE memory 6-1. The short-time exposure image data is read outfrom SE memory 6-1 in accordance with timing of the long-time exposureimage data. After multiplication processing performed based on anexposure amount ratio, synthesizing process is performed at thesynthesizing circuit 6-4 and compression processing is performed at thecompression circuit 6-5. Here, motion of the object is detected at amotion detecting section 8B provided internally of CPU on the basis ofAF signal from an external AF circuit 39. If no motion is detected, theselector 6-7 is previously switched at the camera signal processingcircuit 6′ so as to output a wide dynamic range, synthesized image whichhas been synthesized and compressed. On the other hand, if a motion isdetected, the selector 6-7 is previously switched so as to output along-time exposure image data which is taken based on a second AFinformation, thereby preventing a synthesized image failed due to motionfrom being outputted.

If the apparatus is set to the forced SL taking mode, a camera signalprocessing circuit for example as shown in FIG. 3 is used. The forced SLtaking mode is executed by effecting control at CPU 8 so that SLsynthesized image be always outputted from the selector 6-7.

Further, in this embodiment, when the above described respective takingmodes are selectively set, an indication of the set taking mode isdisplayed together with an image by each taking mode on the LCD displaysection 31 (13), etc. In particular, when the recording mode has beenset by the R/P changeover switch button 26, an indication of theprevious (directly previous) taking mode is displayed on the taking modedisplay section. When a taking mode is set anew by the mode settingbuttons 30, an indication of the newly set taking mode is displayed. Ina manner of displaying image taking modes on the LCD display section 31:“SL-OFF” is displayed as shown in FIG. 5A when set to the normal takingmode where SL taking is not to be performed; “SL-ON” is displayed asshown in FIG. 5B when set to the forced SL taking mode; “SL-AUTO” isdisplayed when set to the automatic SL taking mode. Further, since thecase of executing SL taking and the case of executing a normal takingwithout executing SL taking are included when set to the automatic SLtaking mode, it is preferable to display these for example as“SL-AUTO-ON”, “SL-AUTO-OFF”. Furthermore, in FIGS. 5A and 5B, numeral 41denotes dynamic range (D range) represented by a bar graph, indicatingthat it in the case of forced SL taking mode (SL-ON) is twice as greatas in the case of the normal taking mode (SL-OFF). It should be notedthat the indication of the respective taking mode on the image ineach-taking mode can be switched ON/OFF for its displaying or erasing.

While the above described embodiment has been shown as that in whicheach of the above described taking modes is set by the mode settingbuttons 30, each taking mode can also be set by providing a ternaryslide-type switch as one of the input keys for example as shown in FIG.6. It is shown as set to the forced SL taking mode in FIG. 6A, to theautomatic SL taking mode in FIG. 6B, and to the normal taking mode inFIG. 6C.

Further, the above embodiment has been shown as that in which theapparatus can be set to the three image taking modes, i.e., normaltaking mode, automatic SL taking mode, and forced SL taking modes.However, the setting can also be a combination of the normal taking modeand automatic SL taking mode, of the automatic SL taking mode and forcedSL taking mode, or of the normal taking mode and forced SL taking mode.

Furthermore, the selected state can be also made known by representingone of the plurality of modes such as the normal taking mode (SL-OFF)without displaying its indication while displaying indication of theother modes for example as “SL-ON” or “SL-AUTO”.

A second embodiment will now be described. The present inventionpremises an image pickup apparatus having SL image taking function. Inperforming SL taking, the suitability for SL taking is automaticallydetermined or is manually determined on the basis of various informationrelated to the SL taking so as to decide on ON/OFF switching of SLtaking. In the second embodiment, such information related to SL takingis displayed on the LCD display section. By thus displaying therespective degree or extent of each information related to SL taking onthe display section as an information parameter, it is possible in thecase of the automatic SL taking mode to recognize how ON/OFF switchingof SL taking has been made based on what state of the various types ofinformation, and in the case of manually setting SL taking to suitablyperform ON/OFF switching of SL taking on the basis of informationrelated to SL taking.

In respect of SL taking, the types of information for determining itssuitability are as follows. First, among the information related SLtaking based on previously taken image data is information on motion ofthe object as -previously described in the first embodiment. Since apresence of motion in the object results in a failure of SL synthesizedimage, it is an important information in switching ON/OFF of the SLsynthesized image. Accordingly, an occurrence or non-occurrence ofmotion is displayed as information for determining the suitability of SLtaking. Further, in respect of motion of the object, since correction ispossible if the amount of motion is within an allowable range forcorrection, the amount of motion is displayed in addition to theoccurrence or non-occurrence of motion as a determination makinginformation. By thus obtaining information for switching ON/OFF of SLtaking from previously taken image data, an accurate determinationmaking information can be obtained.

Among the types of information obtained before the taking of image fordetermining the suitability related to SL taking are: information onmotion of the object obtained on the basis of AF or AE signal from anexternal AF circuit or external AE circuit; a camera shake informationbased on a detection signal from a camera shake detection circuitconsisting of an acceleration sensor or the like; etc. Since anunsuitable synthesized image results if synthesis is performed when acamera shake occurs, it is effective to display a suggestion for takingan image over again. Further, when the object has been detected as in abacklighted condition from AE information previously obtained on thebasis of image data from CCD image pickup device before the taking ofimage or from AE information obtained from an external AE circuit, it ispreferable to generate an SL synthesized image by means of SL taking,since the image data is likely to be of wide dynamic range when it is ina backlighted condition. Accordingly, it is also effective to displayinformation on backlighted condition. Furthermore, dynamic range,luminance difference, histogram of luminance, etc., which are the typesof information related to the brightness of object are also effective asSL taking information and preferably displayed.

Further, among the image taking conditions, etc., to be set on thecamera before the taking of image, information on strobe emission modesis mentioned first as the camera setting information serving as thesuitability determining information related to SL taking. When image istaken in a strobe mode, motion of the object can in effect be stoppedeven when the object is moving, by taking image twice at differentexposure amounts in a short time period with causing strobe emission.Since it is thus possible to obtain an SL synthesized image without afailure, the strobe emission mode is an effective information as the SLtaking condition and is preferably displayed. Shutter speed is the oneto be mentioned next among the types effective as SL taking information.A slow shutter speed results in a larger motion of object and is notsuitable for SL taking. A high shutter speed becomes suitable for SLtaking, since motion of the object can be reduced. Accordingly, ashutter speed is an effective information as SL taking information andis preferably displayed. Further, if, for example, the user effects spotmetering in setting exposure, it is most likely the case where anattempt is made to take image with performing spot metering because of abacklighted condition. It is thus fitting to perform SL taking when setto a spot metering mode. Accordingly, the spot metering mode is aneffective information for SL taking and is preferably displayed.

Furthermore, with a camera having a consecutive photographing function,since SL taking cannot be performed when in a consecutive taking mode,the SL taking must be switched OFF. Since too much motion is not likelyto be involved in a scenery (distant view) photographing mode, SL takingis preferably turned ON when set to this mode. Since a large motion ofobject is likely in a sports photographing mode, SL taking is preferablyturned OFF when set to this mode. Moreover, if set to a macro-strobephotographing mode, SL taking is suitable similarly as in the strobemode. As the above, those set information as of exposure setting (spotmetering), consecutive, scenery, sports, macro-strobe taking, etc., arethe types of information effective for the suitability determination ofSL taking and are displayed.

With a camera having zoom, since a higher zoom ratio results in amagnified motion and is not suitable for SL taking, it is necessary toturn OFF SL taking. Accordingly, a zoom ratio, too, becomes an effectiveinformation for switching ON/OFF of SL taking and thus is displayed.Further, when the image pickup apparatus is so constructed as to causean externally connected personal computer or the like to perform thegeneration processing of SL synthesized image, it is necessary in SLtaking to store image data corresponding to two frames of differentexposure amounts to a memory card. Means for detecting the remainingmemory capacity of the memory card is thus provided to detect theremaining memory capacity. Since SL taking cannot be performed when theremaining memory capacity has become less than the capacity for storingimage corresponding to two frames, SL taking is turned OFF and image istaken normally. Accordingly, the remaining capacity of memory, too, is anecessary information for SL taking and is displayed.

An indication of the suitability determining information obtained inconnection with SL taking as described above is displayed on the LCDdisplay section 31 (13) as shown in FIG. 7. By looking up suchindication, if SL taking is turned OFF when set to the automatic SLtaking mode, i-t is easy to identify which one of the information isunfitting and, if SL taking is to be performed manually, it is easy todetermine whether each information is suitable for SL taking. It is alsopossible that information related to SL taking be displayed on theinformation displaying LCD 36, instead of being displayed together withan image as shown in FIG. 7. Further it may be so constructed that theseindications can be turned ON/OFF.

A third embodiment will now be described. The above described secondembodiment has been shown as that in which information necessary fordetermining the suitability for the generation of synthesized image isdisplayed on the display means. In some cases, however, it is difficultto manually determine at once whether it is suitable or unsuitable fromthe information displayed on the display means. In the third embodiment,this point is improved such that information obtained at each stage isdisplayed together with a determination result as to whether it issuitable for the generation of synthesized image.

In an actual method of display, a determination result for eachinformation parameter to be used as the SL taking conditions and adetermination result of the suitability of SL taking as a whole aredisplayed. For example, as shown in FIG. 8A, if all the informationparameters are suitable for SL taking, an indication of “SL Suitable” 43is displayed together with the respective information parameters 42. Onthe other hand, if unsuitable information parameter exists, “NG” mark 44is displayed for the unsuitable information parameters as shown in FIG.8B and at the same time an indication of “SL Unsuitable” 45 is displayedto indicate that SL taking is unsuitable as a whole. It is then alsopossible as shown in FIG. 8B to additionally provide for thoseunsuitable information parameters an indication of suitable range 46 forindicating an extent by which “SL Suitable” can be achieved.

By displaying such indication, the reason for unsuitableness of SLtaking can be confirmed at once. Depending on the cause ofunsuitableness, it is possible to achieve suitable conditions bychanging the image taking conditions. Further, if a suitable range isdisplayed, the level of unsuitableness can be comprehended and it ispossible to know the extent of change by which suitable conditions canbe achieved.

The displaying of each information parameter to be used as theconditions for determining suitability of SL taking will now bedescribed. First, the case of displaying information of motion of theobject will be described below. If motion of the object is not detected,an indication of “SL Suitable” is displayed together with an indicationof “Motion NO” or displaying of nothing. If motion is present, anindication of “SL Taking Unsuitable” is displayed at the same time ofdisplaying of “Motion YES, NG”. Further, if the amount of motion iswithin an allowable range for correction, an indication of “SL Suitable”is displayed at the same time of displaying “Motion Correction ON”. Ifthe amount of motion exceeds the allowable range for correction, anindication of “SL Unsuitable” is displayed at the same time ofdisplaying of “Motion Correction NG”. Furthermore, in respect of motioncorrection, it is also possible to display a motion correction allowablerange 47 by a bar graph as shown in FIG. 9, so as to display thedetected range of motion and/or direction of motion. It should be notedthat, in FIG. 9, numeral 48 denotes an object which has been moved.

The displaying of camera shake information to be used as information fordetermining the suitability of SL taking will now be described. Ifcamera shake is not detected, an indication of “SL Suitable” isdisplayed at the same time of displaying or nondisplaying of “CameraShake NO”. If camera shake has been detected, an indication of “CameraShake YES NG” and an indication of “SL Unsuitable” are displayed. Ifcorrection of camera shake is possible, an indication of “SL Suitable”is displayed at the same time a mark of “Shake Correction ON”. Ifcorrection of camera shake is not permissible, an indication of “ShakeCorrection NG” and an indication of “SL Unsuitable” are displayed.

In the case where information on detection of a backlighted condition isused as information for determining the suitability of SL taking, if abacklighted condition is detected, an indication of “Back Light YES” andan indication of “SL Suitable” are displayed. If a backlighted conditionis not detected, an indication of “Back Light NO NG” and an indicationof “SL Unsuitable” are displayed. Further, in the case where the typesof information related to the brightness of object (dynamic range,luminance difference, histogram of luminance, etc.) are used asinformation for determining the suitability of SL taking, if dynamicrange is wide, an indication of “D Range Wide” and an indication of “SLSuitable” are displayed. If dynamic range is narrow, an indication of “DRange Narrow NG” and an indication of “SL Unsuitable” are displayed. Inany of the cases of a dark object, small luminance difference and nosaturation of luminance, an “NG” mark and an indication of “SLUnsuitable” are displayed.

In the case where information set on the camera for image taking is usedas information for determining the suitability of SL taking, for examplewhen set to a strobe emission mode, an indication of “SL Suitable” isdisplayed at the same time of an indication of “Strobe ON”. If it is setto non-emission of strobe, an indication of “SL Unsuitable” is displayedat the same time of an indication of “Strobe OFF NG”. In the case ofshutter speed, if set to a high speed, an indication of “SL Suitable” isdisplayed at the same time of indicating the shutter speed. If it is setto a slow speed, an indication of “SL Unsuitable” is displayed at thesame time of an indication of the shutter speed and “NG”. In respect ofsetting of exposure, when set to a spot metering mode or manual exposurecorrection mode, an indication of “SL suitable” is displayed at the sametime of its indication. In the case of other exposure setting, anindication of “NG” is added to an indication of such setting and at thesame time an indication of “SL Unsuitable” is displayed. In respect ofsetting of image taking modes (consecutive, scenery, sports, macrostrobe), when set to scenery or macro strobe taking, an indication of“SL Suitable” is displayed at the same time of its indication. When setto consecutive or sports mode, an indication of “NG” is added to itsindication and at the same time an indication of “SL Unsuitable” isdisplayed. In the case of setting a zoom ratio information, if in a wide(low-ratio) setting, an indication of “SL Suitable” is displayed at thesame time of its indication. If in a telephoto (high-ratio) setting, anindication of “NG” is added to the displaying of such setting and at thesame time an indication of “SL Unsuitable” is displayed. Further, whenthe remaining capacity of memory is used as information for determiningthe suitability of SL taking, the remaining capacity is indicated by abar graph, etc., and at the same time, if a capacity corresponding totwo frames or more is left, an indication of “SL Suitable” is displayed.If less than that corresponding to two frames, “NG” is added to theindication of remaining capacity concurrently of displaying “SLUnsuitable”.

In the above description, when suitableness or unsuitableness as a wholeof SL taking is indicated, the displaying is performed by includingsuitableness or unsuitableness of each information parameter to be usedas information for determining the suitability of SL taking at the sametime of displaying “SL Suitable” or “SL Unsuitable”. However, it is alsopossible to indicate only those information parameters of “SLUnsuitable”, i.e., to which “NG” mark is added while without indicatingthose information parameters which are suitable for SL taking. It isfurthermore possible to switch the setting between the case ofdisplaying suitableness or unsuitableness of SL taking as a whole at thesame time of the detailed displaying related to each informationparameter and the case of displaying only suitableness or unsuitablenessof SL taking as a whole without displaying an indication related to eachdetailed information parameter.

Further, it is also possible to render the displaying related to eachinformation parameter at the respective steps of recording orreproduction in the image pickup apparatus. In particular, after settingthe conditions of image taking to the camera, information parameterbased on each set condition is displayed and at the same time a resultof determination of the suitability of SL taking is displayed. Ifunsuitable, an indication of warning is displayed by adding “NG” markthereto. This can be reflected in changing the set conditions, etc.Further, after setting AE and before taking image, a determinationresult on the suitability of SL taking is displayed at the same time ofindicating each information parameter obtained before the taking. Ifunsuitable, an indication of warning is displayed by adding “NG” markthereto. It is thereby possible to effect a change in the takingconditions, etc.

Furthermore, after the taking of image, SL suitability is determined onthe basis of the information parameters obtained from the previouslytaken image data. If unsuitable, an indication of warning is displayedby similarly adding “NG” mark thereto. A decision is thereby made forexample about retaking of image. Moreover, a determination result on SLsuitability can be indicated even after the processing of SL synthesizedimage; an indication of warning, if unsuitable, can be used indetermining whether it should be recorded to the memory card 15 or beerased. Even at the time of reproduction, a determination result on SLsuitability can be displayed for the reproduced SL synthesized image; anindication of warning can be displayed, if unsuitable, so as to be alsoused in determining whether it should be erased, etc.

It should be noted that, while the above has been shown as that in whicheach displaying is shown on the LCD display section 31, it is alsopossible that the displaying be made on the information displaying LCD36 or be displayed on a separately provided LCD display section.Further, the indication of warning to which “NG” is added and/or theindication of “SL Unsuitable” may be indicated not only visually butalso as a warning sound of buzzer or the like.

A fourth embodiment will now be described. The above described thirdembodiment has been shown as that in which an indication of SLsuitability as a whole is displayed at the same time of acquiringvarious information parameters to be used as the conditions fordetermining whether SL taking is suitable, thereby indicating respectivesuitability by determining their suitability for SL taking. In somecases, however, such determination result of SL suitability and thetaking mode set by the user may not correspond. In the fourthembodiment, the fact of inconsistency is indicated when the taking mode(ordinary taking mode, forced SL taking mode, automatic SL taking mode)set by the user does not correspond to the displayed determinationresult of SL suitability as a whole determined on the basis of variousinformation parameters to be used as the conditions for determiningsuitability of SL taking, so as to prevent an unsuitable SL image takingpossibly resulting in a degraded image quality, etc., from beingperformed.

In other words, the determination result and the set taking mode do notcorrespond to each other for example in the case where “SL Suitable” isdetermined from the various information parameters but the normal takingmode is set or in the case where the forced SL taking mode is set whenit is determined as “SL Unsuitable”. Since a suitable image cannot beobtained if these are left unchanged, the fact of inconsistency isindicated so as to give a warning.

FIG. 10A shows a manner of-warning by displaying an indication of“Inconsistency” 49 when, even though it is determined as “SL Suitable”,the normal taking mode (SL-OFF) is set. FIG. 10B shows a manner ofdisplaying an indication of “Inconsistency” 49 when, even though it isdetermined as “SL Unsuitable”, the forced SL taking mode (SL-ON) is set.

A fifth embodiment will now be described. The present invention relatesto image pickup apparatus having SL image taking function for obtainingwide dynamic range, synthesized image by means of synthesis of imagesignals which are obtained by taking image twice with changing exposureamount. In the present embodiment, displayed are: the ratio of exposureamounts (exposure time, emission amount) of the image signals of twoframes of different exposure amounts which are to be subjected to thegeneration processing of wide dynamic range, synthesized image; and/orthe dynamic range of the synthesized image to be generated by thesynthesizing process. Further, in the case where it is possible toselect one from a number of exposure amount ratios, a predeterminedexposure amount ratio is set by the selection and is indicated.

FIG. 11A shows an example where the case of an exposure amount ratio of1:4 and a dynamic range of 80 dB is indicated by characters and inaddition the exposure amount ratio is represented by a bar graph. Itshould be noted that, of the bar graph in FIG. 11A, the black portionrepresents a proportion of short-time exposure 51 and the framed whiteportion represents a proportion of long-time exposure 52. FIG. 11B showsthe state of setting the exposure amount ratio of 1:4 by selection inthe case where an exposure amount ratio can be selected from 1:2, 1:4,1:8, 1:16. In a case such as the above where a definite exposure amountratio can be set by selecting from a number of exposure amount ratios,an exposure amount ratio is selectively indicated by means of the menusetting buttons 32 shown in FIG. 2 and the “+” button, “−” button and“OK” button are operated to set a predetermined exposure amount ratio.

A sixth embodiment will now be described. In general, with a camerahaving function for generating wide dynamic range, synthesized image,two images are taken by previously setting exposure amount ratiothereof. The exposure amount ratio of the two images actually taken,however, is not necessarily the same as the set value. If they aresynthesized in such case, there is a disadvantage that a discontinuityin gradation or the like tends to occur at the seam between the twoimages. This embodiment intends to mitigate this problem.

Specifically, in this embodiment, a camera having function forgenerating wide dynamic range, synthesized image includes exposureamount correction means so that a correction of exposure amount isperformed when a taking mode requiring exposure amount correction hasbeen set and at the same time an operation status such as the occurrenceor nonoccurrence of correction at the exposure amount correction meansis indicated on the display means.

In particular, it is so constructed as to perform an exposure amountcorrection when a strobe image taking mode has been set. In other words,when taking image by using a strobe, the exposure amount depends not onthe shutter speed but on the emission amount of the strobe. Since thestrobe emission amount cannot so accurately be controlled, aconsiderable variance may occur in the exposure amount. Accordingly,exposure amount is corrected when a strobe mode is set.

The correcting operation of exposure amount is performed as follows.Image data with a smaller exposure amount and image data with a greaterexposure amount obtained by two times of image taking using strobeemission are stored to the two memories, i.e., SE memory 6-1 and LEmemory 6-2 of the camera signal processing circuit shown in FIG. 3.These are supplied to CPU 8 and regions are extracted of those withoutlack of detail at low level portion in the SE image data and thosewithout lack of detail at high level portion in the LE image data. SumsΣSE, ΣLE of pixel data of the extracted regions are obtained. An actualexposure amount ratio A′ is obtained by the ratio ΣLE/ΣSE of the two.The synthesizing process is performed by multiplying the low exposureimage data SE and the actual exposure amount ratio A′. A discontinuityin gradation at the seam between the two image data is therebyprevented.

The exposure amount is thus corrected by the exposure amount correctionmeans. In the present embodiment, such operation status of the exposureamount correction means, i.e., whether exposure amount is to becorrected or whether it has been corrected is displayed on the displaymeans before or after the correction. If correction has been performed,an indication of exposure amount ratios before and after the correctionand extent of the correction, etc., is additionally displayed. By thusdisplaying such indication, it is possible to confirm not only theoccurrence or non-occurrence of correction of exposure amount ratio butalso a shift in exposure amount ratio and/or dynamic range based on thecorrected exposure amount ratio.

FIG. 12A shows a manner of displaying in the case where exposure amountratio is to be corrected, representing an example of displaying anindication 53 of “Correcting Exposure Ratio” before the correction or“Corrected Exposure Ratio” after the correction, the corrected exposureamount ratio (1:9) and correcting rate (1.25 times). FIG. 12B shows amanner of displaying in the case where correction of exposure amountratio is not to be performed, representing an example where anindication 54 of “Not Correcting Exposure Amount Ratio” is displayed. Itshould be noted that, in this case, it is also possible to indicate thestatus of not performing correction by displaying nothing.

A seventh embodiment will now be described. In image pickup apparatushaving function for generating wide dynamic range, synthesized image, afailed, synthesized image is outputted if the object has been moved atthe time of taking two images at different exposure amounts. When amotion has been detected, therefore, the generation processing ofsynthesized image is not usually performed. However, when the detectedmotion amount has been relatively small and determined at CPU 8 aswithin an allowable range for correction, the motion is corrected andthe generation processing of synthesized image is performed. In thepresent embodiment, the correction amount of motion is indicated on thedisplay means at the same time of the manner of operation before andafter performing such motion correction.

In a technique for correcting motion, if, for example, regions in ahorizontal direction are taken into consideration, values are used ofpixels A, B in regions without an occurrence of motion, at a suitabledistance d for performing correction from the two ends of the region tobe corrected of motion. The A, B pixels are determined as at two endsand the motion is corrected by interpolating the region to be correctedof motion so as to uniformly change pixel values between the two.

FIG. 13A shows a manner of displaying in the case of correcting motion,representing an example where an indication 55 of “Correcting Motion”before the correction or “Corrected Motion” after the correction and acorrection amount (10% of angle of view from left and right sides) 56are displayed together. FIG. 13B shows a manner of displaying in thecase of not correcting motion, representing an example where anindication 57 of “Not Correcting Motion” is displayed. It should benoted that, in this case, it is also possible to indicate the status ofnot performing correction by displaying nothing.

An eighth embodiment will now be described. In this embodiment, an imagepickup apparatus having function for generating wide dynamic range,synthesized image is provided with three image taking modes, i.e., anormal taking mode for generating image pickup signals corresponding toone frame from CCD image pickup device, a forced SL taking mode forforcing a generation of SL synthesized image, and an automatic SL takingmode for selectively generating SL synthesized image automatically onthe basis of information of the object or of image taking conditions seton the camera. The actual ON/OFF status of the generation processing ofSL synthesized image due to the setting made by selecting one from thesetaking mode is indicated on the display means.

By displaying such ON/OFF status of the generation processing of SLsynthesized image, it is readily possible to confirm whether thegeneration processing of SL synthesized image will actually be performedor whether it has actually been performed. Such displaying can beeffected at various stages during the recording process. In particular,as shown in the flowchart of FIG. 14, it can be displayed for exampleafter the setting of taking mode, at the time of detection of AEinformation, before the taking of image, before the generationprocessing of SL synthesized image, before the recording, and directlyafter the recording. Here, if it is displayed before the taking ofimage, the image taking conditions can be changed by considering suchdisplayed information. Further, since SL image taking can be switched toON or OFF if it is displayed before the generation processing of SLsynthesized image, it can be used as information based on which the usermakes a decision as to whether to take image in the normal taking modeor to take image in the forced SL taking mode. Furthermore, if displayedbefore the recording, it can be used for example as information formaking a selection where image is recorded when SL processing is ON butis erased when SL processing is OFF. Moreover, if displayed after therecording, it can be used as information for deciding storage or erasingby displaying the fact that SL processing of the recorded image was ONor OFF.

FIGS. 15A and 15B each show a displaying manner of ON/OFF of SLsynthesizing process. FIG. 15A shows a manner of displaying the statewhere SL synthesizing process is OFF in the automatic SL taking mode,indicating in the upper row that the apparatus is in the automatic SLtaking mode (SL-AUTO) and in the lower row that SL synthesizing processis OFF (SL-OFF). FIG. 15B shows the state where SL synthesizing processis ON (SL-ON) in the automatic SL taking mode (SL-AUTO). It should benoted that, in FIGS. 15A and 15B, a bar graph 58 represents dynamicrange.

Further, an indication of ON/OFF of SL synthesized image can bedisplayed in the form of a list as shown in FIG. 16, such thatinformation as to whether it is an SL synthesized image or is an imagetaken in the normal taking mode is stored to a part of RAM within CPU 8or DRAM 11 with respect to each of all the previously taken images.Referring to FIG. 16, the left end column indicates frame numbers and SL(SL synthesized image) or NOR (normal image) is displayed in amanner-corresponding thereto. Further, regarding the displaying withrespect to all the previously taken images, since a processed image isto be recorded on the memory card 15, information as to whether it is anSL synthesized image or a normal image can be stored as an incidentalinformation of image file when the image is recorded to the memory card15.

By storing as described above ON/OFF of SL processing, i.e., informationof SL synthesized image or normal image, it is possible also at the timeof reproduction to readily identify the taken image as to whether it isan SL synthesized image or a normal image.

A ninth embodiment will now be described. In this embodiment, SLsynthesized image is displayed on the display means so that an actual SLsynthesized image can be confirmed. The SL synthesized image can eitherbe an SL synthesized image corrected of exposure amount ratio or an SLsynthesized image corrected of motion, thereby a synthesized imagewithout a failure can be displayed. Further, in displaying SLsynthesized image, it is also possible as shown in FIG. 17 tosuperimpose information relating to the image taking for generating theSL synthesized image. The types of information to be superimposed mayinclude image taking information parameters (motion, backlightedcondition, etc.), SL suitability, exposure amount ratio, the occurrenceor non-occurrence of correction of exposure amount ratio, the occurrenceor non-occurrence of correction of motion, information for representingbrightness, and information for representing dynamic range.

Further, in a modification of this embodiment, it is also possible toindicate on the display means not only an SL synthesized image but alsoa normally taken image (long-time exposure image). When SL synthesizedimage and normally taken image are to be displayed, switching can bemade to alternately display an ordinarily taken image (SL-OFF) 61 and anSL synthesized image (SL-ON) 62 as shown in FIG. 18, or an ordinarilytaken image 63 and an SL synthesized image 64 be displayed together asshown in FIGS. 19A and 19B. It is thereby possible for the user toobserve both images to select one or the other as an image to berecorded. In this case of concurrent displaying, it is also possible toindicate which one of the images is currently selected by the user (theillustrated example indicating by the dotted mesh the fact that SLsynthesized image is selected). In such case, it is preferable toadditionally display an indication (SL Image/Normal Image SelectionFrame) 65 of the fact that the apparatus is in a mode for selectingimage.

In another modification, as shown in FIGS. 20A and 20B, a short-timeexposure image (SE image) 66 and a long-time exposure image (LE image)67 before the SL synthesizing process can be displayed alternately orconcurrently. By thus displaying a short-time exposure image and along-time exposure image, it is possible to confirm with respect to theshort-time exposure image whether lack of detail at high level portionoccurs in those portions (portions of tree and house) intended to beacquired and to confirm with respect to the long-time exposure imagewhether lack of detail at low level portion occurs in the portion(person) intended to be acquired. As a result of confirming these, it ispossible to expect that a suitable SL synthesized image can be obtained.

In displaying images as the above, the displaying of each image can beeffected at various points including before and after the SLsynthesizing process such as before the recording or after therecording. If displayed before the recording, the images can beconfirmed at the time of changing the image taking conditions, selectingnormally taken image or SL synthesized image, or making a selection asto recording or erasing. Further, if displayed after the recording, theimages can be confirmed when making a selection as to storage or erasingof the recorded image.

Further, in still another modification, the short-time exposure imageand long-time exposure image taken for the generation of an SLsynthesized image are recorded intact as two pieces of image data to thememory card without being subjected to synthesizing process. At the timeof reproduction, then, the above described two pieces of image data areread out and each image is displayed. If, as a result of observing theseimages, they are determined as those from which an SL synthesized imageshould be generated, SL synthesizing process is performed and they arereproduced and displayed as an SL synthesized image.

A tenth embodiment will now be described. In the above describedembodiments, various information parameters and/or image taking modesare set and these types of set information are displayed at variousstages before and after the taking of image. In the present embodiment,the suitability of image taking mode and information parameter isautomatically determined at various stages. If before the taking ofimage, directions are given for a change in the setting of informationparameters or set image taking mode so that a change in the setting canbe made at various stages. Further, if after the taking of image,directions for retake are given before and after the SL processing orbefore and after the recording so that image can be taken anew. The SLsuitability is thereby automatically determined and it becomes possibleto take image of an improved image quality.

The above described change in the setting of information parameter orimage taking mode or the operation of retaking may be performed eithermanually or automatically. Here, if the setting of information parameteris to be changed, the apparatus is brought into a setting changing modeas shown in FIG. 21A, where an indication 71 of the fact that thesetting is going to be changed is displayed and the items to be changedand their values before and after the change are displayed in acombination. Further, in the case of retaking image, an indication 72 ofthe fact that image is going to be taken anew and, if the retake is tobe performed automatically, an indication of the fact that it isautomatic are displayed as shown in FIG. 21B and, in addition, anindication of confirmation by the user, if made, is preferablydisplayed. Such technique for automatically performing change in settingor retake can also be applied to an ordinary image pickup apparatuswhich is not provided with SL image taking function.

An eleventh embodiment will now be described. In this embodiment,information of brightness of desired portions, for example of thedarkest portion and the brightest portion, of object are displayed onthe display means together with an image of the object. In particular,as shown in FIG. 22A, the brightest portion (the house) {circle around(1)}, the darkest portion (the torso of the person) {circle around (3)},and the portion at an intermediate brightness (the head of the person){circle around (2)} of the object are pointed out on the image as theportions of which brightness is to be indicated. At the same time,luminance of each of the portions {circle around (1)}, {circle around(2)}, {circle around (3)} is correspondingly displayed on a bar graphwhich represents dynamic range. The portions {circle around (1)},{circle around (2)}, {circle around (3)} of which brightness is to beindicated can be moved at will to desired portions.

Further, as shown in FIG. 22B, luminance difference can also bedisplayed in combination. Furthermore, as shown in FIG. 22C, it is alsopossible to indicate by means of a numeric value and bar graph thepercentage of the high luminance portion (the portions of tree and housesurrounded by dotted lines in the illustrated example) to the wholeimage. It should be noted that the case of a larger percentage of highluminance portion is suitable for the generation processing of SLsynthesized image. A threshold is set within the overall range ofluminance and those values above such threshold value are determined ashigh luminance portions. The threshold can be varied by means of numericvalues or bar code setting.

The above described indication of brightness can be displayed at variousstages of recording process, i.e., before and after the taking of image,before and after the SL processing, before and after the recording, etc.If displayed before the taking of image, it can be used as determininginformation for example for making a change in the image takingconditions. If displayed after the taking of image, it can be used asdetermining information for example in the case where image is to beretaken by changing the image taking conditions. If displayed after SLprocessing, it can be used in determining whether SL synthesized imageis to be recorded or to be erased. If displayed after the recording, itcan be used also in determining whether the SL synthesized image is tobe erased and at the same time it can be recognized as an incidentalinformation of the recorded image.

A twelfth embodiment will now be described. Usually, an exposure amountratio is previously set of two images of different exposure amounts tobe used for the generation of SL synthesized image and, on the basis ofsuch exposure amount ratio, dynamic range of synthesized image is set.In the present embodiment, however, object portions of an actual imagedesired to be acquired is designated by the user so that a dynamic rangecan be set at will by means of a visual method.

In particular, as shown in FIG. 23A, an image taken in at the time of AEor an image obtained by a previous image taking is displayed. A darkestnarrow region (the torso of the person) 75 is designated as a spotlocked area and a darkest portion luminance information is obtained fromthe lowest or mean luminance value of such designated portion. In asimilar manner as shown in FIG. 23B, an image taken in at the time of AEor an image obtained by a previous image taking is displayed and abrightest portion luminance information is obtained from the highest ormean luminance value in the brightest narrow region (the house building)76. The shutter speed-is then set respectively for two images so thatthe darkest portion luminance information and brightest portionluminance information obtained in the above described manner arerespectively brought to suitable levels in an SL synthesized image. Thedynamic range of synthesized image is set on the basis of the setshutter speeds. In a modification, it is also possible that one of thedarkest portion or the brightest portion is previously provided as anestablished value so that operation is simplified by setting only theother. It is furthermore possible to set a suitable exposure portionbased on which a brightness information serving as the center of dynamicrange is set.

It should be noted that, in order to designate a desired narrow regionwithin an image, the framing of a previously set narrow region is setand locked on a desired region on the image for example by using themenu buttons so as to designate it by means of marking.

A modification of this embodiment will now be described. In thismodification, a short-time exposure image and a long-time exposure imageare directly set by the user so that dynamic range of synthesized imageis set on the basis of the exposure amount ratio of these images. Inparticular, a short-time exposure image SE is displayed as shown in FIG.24A and the user is to set an exposure amount by considering to whatextent the range without lack of detail at high level portion should be.Further, the long-time exposure image LE is displayed as shown in FIG.24B, and the user sets an exposure amount by considering to what extentthe range without lack of detail at low level portion should be. Thedynamic range of synthesized image is then set on the basis of exposureamounts of the two images of which the exposure amounts are set.

A thirteenth embodiment will now be described. In general, an exposurecontrol system in those image pickup apparatus called as electroniccamera (digital camera) uses the so-called video AE system in which anoutput information of image pickup device is used to change aperturestop or shutter speed. The reason for this is that, since dynamic rangeof image pickup device is narrow, a small error in exposure greatlyaffects the image quality. For this reason, an exposure control systembased on an external photometric device such as those used in silversalt cameras is hardly employed due to the fact that the externalphotometric device is poor in accuracy and that variances in imagepickup device and external photometric device cause a reduced accuracyin exposure control.

With the video AE system, however, an accurate exposure control cannotbe performed if based only on an output information of one frame due tothe narrow dynamic range of image pickup-device. A technique is thusused to narrow down to an optimum exposure by means of a feedback loopsystem by gradually changing the quantity of incident light. For thisreason, several to several tens of images are required from the start ofAE to the determination of an optimum value. Since, especially, therecent cameras with a larger number of pixels are becoming to require alonger time period for the outputting of one frame, there is a problemof an increased time-lag of shutter and dissipation power.

This embodiment has been made to eliminate this problem. Itsconstruction will be described below by way of a block diagram of FIG.25. In this embodiment, the functions of the exposure control means,exposure determining means, synthesizing means, etc., are achievedwithin CPU 8. What is denoted by numeral 81 is an exposure controlsection, the exposure control section 81 controlling the shutter/stopmechanism 3 and the timing generator (electronic shutter) 18, therebycontrolling exposure amount for the CCD image pickup device 1. Denotedby numeral 82 is a synthesizing section for synthesizing two outputsignals taken at different exposure amounts and outputted from the imagepickup device, and 83 is an exposure determining section for determiningexposure on the basis of the synthesized output signal thus synthesized.

The operation of thus constructed AE apparatus will now be describedwith reference to the flowchart of FIG. 26. First, an initial value “1”is set to the exposure control section 81 and the timing generator 18and the shutter/stop mechanism 3 are set to predetermined valuescorresponding to the initial value “1” (step S1). An image is then takenin the state where exposure amount is set to the initial value “1” andan image “1” is taken into CPU 8 from the CCD image pickup device 1through the amplifier 4, analog-to-digital converter 5, and AE detectioncircuit 7 (step S2). The exposure control section 81 is then set to aninitial value “2” which is different from the initial value “1” and thetiming generator 18 and shutter/stop mechanism 3 are brought topredetermined values corresponding to the initial value “2” (step S3).An image is then taken in the state where exposure amount is set to theinitial value “2” and an image “2” is taken into CPU 8 from the CCDimage pickup device 1 through the amplifier 4, analog-to-digitalconverter 5, and AE detection circuit 7 (step S4). An image is thensynthesized from the image “1” and image “2” at the synthesizing section82 (step S5). An image information is thereby obtained as having a widedynamic range and without lack of detail at low level portion and lackof detail at high level portion. An AE operation is then performed byusing this synthesized image information (step S6). The AE operation ofan optimum, suitable value thereby becomes possible by one operation,making it unnecessary to perform a feedback control.

FIGS. 27A and 27B show the manner of synthesizing image “1” and image“2”. Referring to FIG. 27A, “X” represents the range of incident lightquantity which can be taken in when the exposure control section 81 isset to the initial value “1”, image “1” of dynamic range in suchincident light quantity range being taken in. “Y” represents the rangeof incident light quantity which can be taken in when the initial value“2” is set, image 2 of dynamic range in such incident light quantityrange being taken in. By synthesizing these images “1” and “2”, a widedynamic range, synthesized image as shown in FIG. 27B is obtained. “Z”represents the range of incident light quantity which has been taken inby synthesis.

With the AE apparatus according to this embodiment, if applied to animage pickup apparatus having SL function, the SL synthesizing circuitcan be used also as the synthesizing section of the AE apparatus. If theAE apparatus according to the present embodiment is applied to anordinary electronic camera, its synthesizing section can be constructedby a synthesizing circuit which is rougher than the SL synthesizingcircuit.

As has been described by way of the above embodiments, in accordancewith the first aspect of the present invention, operability can beimproved with a single image pickup apparatus such that image is takenby selecting one taking mode from at least two modes among the normaltaking mode, the forced wide dynamic range taking mode, and theautomatic wide dynamic range taking mode. In accordance with the secondaspect of the invention, it is possible, in the case of manually settingthe generation processing of synthesized image, to make discriminationas to whether or not a previously taken image data is an image datasuitable for the generation of synthesized image by the displaying ofinformation parameter based on the previously taken image data; it isalso possible by the displaying of an information obtained before thetaking of image or information set before the taking of image todetermine whether the generation of synthesized image based on suchinformation is suitable. Further, in the case where the generationprocessing of synthesized image is automatically performed on the basisof the above described information, it is possible to confirm theinformation which is unsuitable to the generation of synthesized image.In accordance with the third aspect of the invention, since adetermination result as to whether it is suitable for the generationprocessing of synthesized image is displayed, the suitability for thesynthesized image generation processing can be quite readily confirmed.In accordance with the fourth aspect of the invention, since informationbecoming unsuitable is displayed as N.G. information, the cause ofunsuitableness can be confirmed and it is thereby possible to achievesuitable conditions by changing the image taking conditions.

In accordance with the fifth aspect of the invention, since a suitablerange of synthesizing process can be displayed together with a numericparameter of information, it is possible to confirm the level of changein the image taking conditions for achieving suitableness. In accordancewith the sixth aspect of the invention, since “inconsistency” isdisplayed when the set taking mode and the result of determination atthe suitability determination means are not suitable to each other, itis possible to prevent an unsuitable taking of image resulting in adegraded picture quality, etc., from being executed. In accordance withthe seventh aspect of the invention, since an exposure amount ratio ofthe image signals corresponding to a plurality of frames of differentexposure amounts is displayed, it is possible to recognize thedifference in exposure conditions of the plurality of images to be takenand the dynamic range if they are combined into a synthesized image. Inaccordance with the eighth aspect of the invention, since the means fordisplaying operation status of the correction means of exposure amountratio is provided, confirmation can be made as to an occurrence ofcorrection of exposure amount ratio; and at the same time, by displayingthe exposure amount ratio before and after the correction, it ispossible to confirm shift in the exposure amount ratio, the dynamicrange based on the corrected exposure amount ratio, etc. In accordancewith the ninth aspect of the invention, since the means for displayingoperation status of the motion correction means is provided, anoccurrence of motion can be confirmed. Further, since the fact of theoccurrence of motion can be seen from an indication of “MotionCorrection”, the resulting degradation in image quality can be easilynoticed. In accordance with the tenth aspect of the invention, since thedisplay means for displaying ON/OFF status of the generation processingof wide dynamic range, synthesized image is provided, it is possible toreadily confirm whether a synthesizing process will be actuallyperformed or whether it has been performed.

In accordance with the eleventh aspect of the invention, since widedynamic range, synthesized image is displayed, it is possible to confirman actual synthesized image. In accordance with the twelfth aspect ofthe invention, when the taking mode and the content of informationparameter are unsuitable to each other, if before the taking of image,the means for directing a change in the setting of taking mode orinformation parameter is provided so that image can be taken withimproving image quality. Further, if after the taking of image, since aretake is directed, it is similarly possible to take image withimproving image quality. In accordance with the thirteenth aspect of theinvention, since the means for displaying brightness information of adesired portion of object together with an object image is provided, thedisplaying of luminance of the darkest portion and the brightest portionof the object for example makes it possible to recognize dynamic rangeand/or suitable exposure amount by numeric values. In accordance withthe fourteenth aspect of the invention, since exposure amounts of theplurality of images are adjusted so that luminance information of thedesignated, desired regions is of suitable luminance levels at the timeof generating wide dynamic range, synthesized image, it becomes possibleto set wide dynamic range of the synthesized image at will by a visualmethod. In accordance with the fifteenth aspect of the invention, theobject regions wished to be included within the dynamic range ofsynthesized image can be readily designated. In accordance with thesixteenth aspect of the invention, since the exposure amounts of theplurality of displayed images are set to desired exposure amounts andthe dynamic range of synthesized image is set on the basis of the setexposure amounts, it becomes possible to set the dynamic range ofsynthesized image at will by a visual method. In accordance with theseventeenth aspect of the invention, since suitable values of exposurecan be decided in a short time period on the basis of the plurality ofoutput information of different exposure amounts, it is possible toprovide an AE apparatus in which the problems of time-lag in shutterand/or dissipation power are solved.

1. An image pickup apparatus comprising: image pickup means capable oftaking images of the same object at a plurality of different exposureamounts to generate image signals corresponding to a plurality of framesof different exposure amounts; and means for generating wide dynamicrange, synthesized image by synthesizing image signals corresponding toa plurality of frames of different exposure amounts obtained by theimage pickup means, said image pickup apparatus further comprising:display means for displaying as a suitability determining information ofthe synthesized image generating process at least an information set forthe image taking among object information or information set for theimage taking that is required in determining whether a suitable widedynamic range, synthesized image can be obtained, wherein said objectinformation is information based on previously taken image data andinformation obtained before the taking of image, and said informationset for the image taking is information set on the image pickupapparatus before the taking of image; suitability determination meansfor determining the suitability to the generation processing ofsynthesized image of at least one information out of said informationbased on previously taken image data, said information obtained beforethe taking of image, and said information set on the image pickupapparatus before the taking of image can be suitably generated; whereinsaid display means displays a result of determination at thedetermination means; and wherein said display means displays a result ofdetermination at said determination means as a numerical parameter ofinformation and at the same time displays a suitable range forsynthesizing process of the information numeric parameter.
 2. An imagepickup apparatus comprising: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means, said image pickup apparatus further comprising: displaymeans for displaying as a suitability determining information of thesynthesized image generating process at least an information set for theimage taking among object information or information set for the imagetaking that is reciuired in determining whether a suitable wide dynamicrange, synthesized image can be obtained, wherein said objectinformation is information based on previously taken image data andinformation obtained before the taking of image, and said informationset for the image taking is information set on the image pickupapparatus before the taking of image; suitability determination meansfor determining the suitability to the generation processing ofsynthesized image of at least one information out of said informationbased on previously taken image data, said information obtained beforethe taking of image, and said information set on the image pickupapparatus before the taking of image can be suitably generated; whereinsaid display means displays a result of determination at thedetermination means; wherein said display means displays informationindicating unsuitable when it is determined as unsuitable by saiddetermination means; and wherein said display means displays a result ofdetermination at said determination means as a numerical parameter ofinformation and at the same time displays a suitable range forsynthesizing process of the information numeric parameter.
 3. An imagepickup apparatus comprising: image pickup means capable of taking imagesof the same object at a plurality of different exposure amounts togenerate image signals corresponding to a plurality of frames ofdifferent exposure amounts; and means for generating wide dynamic range,synthesized image by synthesizing image signals corresponding to aplurality of frames of different exposure amounts obtained by the imagepickup means, said image pickup apparatus further comprising: displaymeans for displaying as a suitability determining information of thesynthesized image generating process at least an information set for theimage taking among object information or information set for the imagetaking that is required in determining whether a suitable wide dynamicrange, synthesized image can be obtained, wherein said objectinformation is information based on previously taken image data andinformation obtained before the taking of image, and said informationset for the image taking is information set on the image pickupapparatus before the taking of image; suitability determination meansfor determining the suitability to the generation processing ofsynthesized image of at least one information out of said informationbased on previously taken image data, said information obtained beforethe taking of image, and said information set on the image pickupapparatus before the taking of image can be suitably generated; whereinsaid display means displays a result of determination at thedetermination means; wherein said suitability determination meansfurther determines whether information obtained as conditions ofgeneration processing for the generation of wide dynamic range,synthesized image is the information suitable for the generationprocessing of wide dynamic range, synthesized image; and said displaymeans displays “inconsistency” when the taking mode set at said modesetting means and the result of determination made at said suitabilitydetermination means are not suitable to each other.
 4. The image pickupapparatus according to claim 3, further comprising means for directing achange in the setting of parameter of said information or in the settingof taking mode or directing a retake when the taking mode set at saidmode setting means and the result of determination made at saidsuitability determination means are not suitable to each other.